Setting tools are used for setting, i.e. anchoring, plugs or other objects downhole. To set a plug, a setting tool may be connected to a running tool coupled to the plug to be set. When the plug has been positioned in the desired position downhole, an axial force is applied via the running tool to the plug, whereby the plug is set downhole and the running tool and/or the setting tool are/is released from the plug.
However, if the setting process fails, e.g. due to malfunction of the mechanical system of the plug or setting tool, the plug may not be appropriately set, whereby the setting tool is not released from the plug. In case of connection to a partly set plug, it may be very difficult, or simply impossible, to extract the setting tool from the well, and then special tools are required. In order to retrieve a stuck tool, more heavy equipment having more power is necessary to pull the tool out, or if the stuck setting tool remains stuck, the tool has to be drilled out, resulting in costly production time being lost.